{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T12:48:21Z","timestamp":1792068501560,"version":"4.4.0"},"reference-count":37,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2025,10,17]],"date-time":"2025-10-17T00:00:00Z","timestamp":1760659200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Science and Technology Council","award":["NSTC 113-2221-E-006-099-MY3"],"award-info":[{"award-number":["NSTC 113-2221-E-006-099-MY3"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Triboelectric nanogenerators (TENG) are mechanical energy harvesters characterized by high sensitivity and simple structure and are currently being widely developed for use in human body motion sensing. Among them, fiber-based TENGs (FTENG) are particularly suitable for wearable human motion sensors due to their unique structure, which offers flexibility, high durability, and comfort. However, studies involving doping to further modify the electrical output characteristics of FTENGs are very limited. Here, we propose an innovative approach that combines graphite (GP) doping with fiber-based TENG fabrication, successfully developing a graphite-doped polyester fiber-based TENG (GP@PET-TENG). Proper graphite doping can increase the amount of transferred charge and thus improve the output electrical performance of TENG, but this method has rarely been explored in FTENG. With the incorporation of 3%wt graphite, the open-circuit voltage of the GP@PET-TENG increased from 103.3 V to 202.1 V, and the short-circuit current increased from 60.7 \u03bcA to 105.1 \u03bcA, compared to the pure polyester fiber based TENG (PET-TENG). The device achieved a maximum output power of 4.15 mW (2.59 W\/m2), demonstrates the capability to charge various capacitors, and successfully lit up 200 LEDs. By attaching the GP@PET tribo-layer to human skin, a single-electrode mode TENG can be formed, which captures the subject\u2019s motion signals through skin contact and separation, converting them into voltage outputs. In fist-clenching and wrist-bending tests, motion-induced voltage signals up to 0.6 V were recorded, demonstrating the potential applications in rehabilitation assistance and mechanical control.<\/jats:p>","DOI":"10.3390\/s25206409","type":"journal-article","created":{"date-parts":[[2025,10,17]],"date-time":"2025-10-17T10:28:36Z","timestamp":1760696916000},"page":"6409","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Enhancing the Output Performance of Fiber-TENG Through Graphite Doping and Its Application in Human Motion Sensing"],"prefix":"10.3390","volume":"25","author":[{"given":"You-Jun","family":"Huang","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jen-I","family":"Chuang","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4068-5713","authenticated-orcid":false,"given":"Chen-Kuei","family":"Chung","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1016\/j.pmrj.2018.06.013","article-title":"Wearable movement sensors for rehabilitation: A focused review of technological and clinical advances","volume":"10","author":"Porciuncula","year":"2018","journal-title":"PM&R"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"102623","DOI":"10.1016\/j.mechatronics.2021.102623","article-title":"A low cost 3-DOF force sensing unit design for wrist rehabilitation robot","volume":"78","author":"Mayetin","year":"2021","journal-title":"Mechatronics"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/j.jare.2020.07.001","article-title":"A review of flexible force sensors for human health monitoring","volume":"26","author":"Cheng","year":"2020","journal-title":"J. Adv. Res."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Hribernik, M., Umek, A., Toma\u017ei\u010d, S., and Kos, A. (2022). Review of real-time biomechanical feedback systems in sport and rehabilitation. Sensors, 22.","DOI":"10.3390\/s22083006"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"137809","DOI":"10.1109\/ACCESS.2021.3118281","article-title":"Robhand: A hand exoskeleton with real-time emg-driven embedded control quantifying hand gesture recognition delays for bilateral rehabilitation","volume":"9","author":"Cisnal","year":"2021","journal-title":"IEEE Access"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"9391850","DOI":"10.1155\/2016\/9391850","article-title":"Force sensing resistor and evaluation of technology for wearable body pressure sensing","volume":"2016","author":"Giovanelli","year":"2016","journal-title":"J. Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"3362","DOI":"10.3390\/s140203362","article-title":"Gait analysis methods: An overview of wearable and non-wearable systems, highlighting clinical applications","volume":"14","year":"2014","journal-title":"Sensors"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Wang, H., Wu, T., Zeng, Q., and Lee, C. (2020). A review and perspective for the development of triboelectric nanogenerator (TENG)-based self-powered neuroprosthetics. Micromachines, 11.","DOI":"10.3390\/mi11090865"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1016\/j.trechm.2021.01.001","article-title":"Wearable triboelectric nanogenerators for therapeutics","volume":"3","author":"Xiao","year":"2021","journal-title":"Trends Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2205438","DOI":"10.1002\/adfm.202205438","article-title":"Recent progresses in wearable triboelectric nanogenerators","volume":"32","author":"Dassanayaka","year":"2022","journal-title":"Adv. Funct. Mater."},{"key":"ref_11","first-page":"359","article-title":"Review of energy harvesting techniques and applications for microelectronics","volume":"Volume 5837","author":"Mateu","year":"2005","journal-title":"VLSI Circuits and Systems II, Proceedings of SPIE, Sevilla, Spain, 9\u201311 May 2005"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1802906","DOI":"10.1002\/aenm.201802906","article-title":"Triboelectric nanogenerator: A foundation of the energy for the new era","volume":"9","author":"Wu","year":"2019","journal-title":"Adv. Energy Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"11893","DOI":"10.1039\/C8TC02964D","article-title":"Toward self-powered photodetection enabled by triboelectric nanogenerators","volume":"6","author":"Wen","year":"2018","journal-title":"J. Mater. Chem. C"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Wang, Z.L., Lin, L., Chen, J., Niu, S., and Zi, Y. (2016). Triboelectric nanogenerator: Vertical contact-separation mode. Triboelectric Nanogenerators, Springer.","DOI":"10.1007\/978-3-319-40039-6"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.nanoen.2016.06.049","article-title":"On the contact behavior of micro-\/nano-structured interface used in vertical-contact-mode triboelectric nanogenerators","volume":"27","author":"Jin","year":"2016","journal-title":"Nano Energy"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Wang, Z.L., Lin, L., Chen, J., Niu, S., and Zi, Y. (2016). Triboelectric nanogenerator: Single-electrode mode. Triboelectric Nanogenerators, Springer.","DOI":"10.1007\/978-3-319-40039-6"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"328","DOI":"10.1016\/j.nanoen.2012.01.004","article-title":"Flexible triboelectric generator","volume":"1","author":"Fan","year":"2012","journal-title":"Nano Energy"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"105067","DOI":"10.1016\/j.nanoen.2020.105067","article-title":"A unified contact force-dependent model for triboelectric nanogenerators accounting for surface roughness","volume":"76","author":"Xu","year":"2020","journal-title":"Nano Energy"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"158636","DOI":"10.1016\/j.cej.2024.158636","article-title":"Advanced electrospun fiber-based triboelectric nanogenerators: From diversified designs to customized applications","volume":"503","author":"Zhang","year":"2025","journal-title":"Chem. Eng. J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5442","DOI":"10.1021\/acsaelm.5c00423","article-title":"Fully Fabric Triboelectric Nanogenerators Based on SWCNH-Coated Cotton Fabric\/UHMWPE: IoT Sensing","volume":"7","author":"Xu","year":"2025","journal-title":"ACS Appl. Electron. Mater."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Kim, H., Nguyen, D.C., Luu, T.T., Ding, Z., Lin, Z.H., and Choi, D. (2023). Recent advances in functional fiber-based wearable triboelectric nanogenerators. Nanomaterials, 13.","DOI":"10.3390\/nano13192718"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2303249","DOI":"10.1002\/adfm.202303249","article-title":"The rising of fiber constructed piezo\/triboelectric nanogenerators: From material selections, fabrication techniques to emerging applications","volume":"33","author":"Li","year":"2023","journal-title":"Adv. Funct. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2100143","DOI":"10.1002\/mame.202100143","article-title":"Advances in Electrospun Fiber-Based Flexible Nanogenerators for Wearable Applications","volume":"306","author":"Arica","year":"2021","journal-title":"Macromol. Mater. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"110297","DOI":"10.1016\/j.nanoen.2024.110297","article-title":"Hydrogen-bond enhanced interior charge transport and trapping in all-fiber triboelectric nanogenerators for human motion sensing and communication","volume":"131","author":"Duo","year":"2024","journal-title":"Nano Energy"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"119926","DOI":"10.1016\/j.carbon.2024.119926","article-title":"PVDF\/N-rGO nanofibers based sustainable triboelectric nanogenerator for self-powered wireless motion sensor","volume":"234","author":"Rana","year":"2025","journal-title":"Carbon"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"106582","DOI":"10.1016\/j.nanoen.2021.106582","article-title":"Porous PDMS conformable coating for high power output carbon fibers\/ZnO nanorod-based triboelectric energy harvesters","volume":"90","author":"Barras","year":"2021","journal-title":"Nano Energy"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1702648","DOI":"10.1002\/adma.201702648","article-title":"3D orthogonal woven triboelectric nanogenerator for effective biomechanical energy harvesting and as self-powered active motion sensors","volume":"29","author":"Dong","year":"2017","journal-title":"Adv. Mater."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Chung, C.K., Huang, Y.J., Wang, T.K., and Lo, Y.L. (2022). Fiber-Based Triboelectric Nanogenerator for Mechanical Energy Harvesting and Its Application to a Human\u2013Machine Interface. Sensors, 22.","DOI":"10.3390\/s22249632"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"106173","DOI":"10.1016\/j.nanoen.2021.106173","article-title":"Nitrogen-doped graphene based triboelectric nanogenerators","volume":"87","author":"Pace","year":"2021","journal-title":"Nano Energy"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"130721","DOI":"10.1016\/j.surfcoat.2024.130721","article-title":"Effect of commercial P25 TiO2 doping in polydimethylsiloxane tribo-film on the output performance of triboelectric nanogenerator and its application","volume":"482","author":"Huang","year":"2024","journal-title":"Surf. Coat. Technol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2400277","DOI":"10.1002\/adfm.202400277","article-title":"Molecular doped biodegradable triboelectric nanogenerator with optimal output performance","volume":"34","author":"Li","year":"2024","journal-title":"Adv. Funct. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"106759","DOI":"10.1016\/j.nanoen.2021.106759","article-title":"Enhanced energy harvesting performance of triboelectric nanogenerator via efficient dielectric modulation dominated by interfacial interaction","volume":"92","author":"Song","year":"2022","journal-title":"Nano Energy"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"104388","DOI":"10.1016\/j.jtice.2022.104388","article-title":"Low-cost micro-graphite doped polydimethylsiloxane composite film for enhancement of mechanical-to-electrical energy conversion with aluminum and its application","volume":"135","author":"Ke","year":"2022","journal-title":"J. Taiwan Inst. Chem. Eng."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"544","DOI":"10.1002\/er.7245","article-title":"A review on applications of graphene in triboelectric nanogenerators","volume":"46","author":"Hatta","year":"2022","journal-title":"Int. J. Energy Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"38469","DOI":"10.1021\/acsami.5c05754","article-title":"A Carbon Nanotube-Doped Polyurethane Nanocomposite-Based Triboelectric Nanogenerator: A Platform for Efficient Mechanical Energy Harvesting and Self-Powered Motion Sensing","volume":"17","author":"Yang","year":"2025","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"110530","DOI":"10.1016\/j.nanoen.2024.110530","article-title":"Triboelectric nanogenerator based on well-dispersed and oxide-free liquid metal-doped conductive hydrogel as self-powered wearable sensor for respiratory and thyroid cartilage signal monitoring","volume":"134","author":"Yang","year":"2025","journal-title":"Nano Energy"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3576","DOI":"10.1039\/c3ee42571a","article-title":"Theoretical study of contact-mode triboelectric nanogenerators as an effective power source","volume":"6","author":"Niu","year":"2013","journal-title":"Energy Environ. Sci."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/25\/20\/6409\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,19]],"date-time":"2025-10-19T04:19:32Z","timestamp":1760847572000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/25\/20\/6409"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,17]]},"references-count":37,"journal-issue":{"issue":"20","published-online":{"date-parts":[[2025,10]]}},"alternative-id":["s25206409"],"URL":"https:\/\/doi.org\/10.3390\/s25206409","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,17]]}}}